I was 100's of miles away on a week-long camping trip in the mountains near Nevada and attending the Reno National Air Races. We found out when we went into town for supplies that day and saw fresh newspapers and people watching playback videos on display TV's in store windows and in bars. What a shock!
The next day we went down to Reno for the first day of the races, but they were suspended due to the emergency "no-fly" rule in effect. Those-in-charge tried to negotiate a waver for the races to go on, but no-go. It was odd to be there and see near-empty stands and a sky free of ANY aircraft or contrail.
We finished our trip and went home, though I noticed how quiet it was while up there. The camp site was near Donner Lake and is under a main air-traffic corridor over the Sierras for small general aviation craft. Normally airplanes were ALWAYS heard and spotted, but the sky was 100% plane-free. Back at home you heard the rare fighter jet with lit afterburners making a dash-run somewhere , but that was it. It was a spooky time.
Any silver linings? We got to experience what the world looked like pre-Wright Brothers

Nothing up there but birds. The quiet was disturbing...how ironic.